Proposals have been made to move part-carrying supports or platens over one or more paths made up of a series of straight path portions which are perpendicular to one another and which make use of an endless belt co-operating with the plate-like body of the part-carrying platen.
Such machines tend to comprise a plurality of different modules to make it possible to build up workshops flexibly. Each module may have a considerable length of path inside it, but in an effort to reduce the total number of drive motors, each module only has one electric motor driving a single very long belt. The path is often tortuous as well as long, and the net result is the application of high forces to the belt inside a module. Thus savings in quantity of belt drive motors can lead to considerable expense in obtaining belts of sufficient strength to withstand said forces.
Preferred embodiments of the invention enable readily available, cheap belts to be used, while still retaining the principle of one belt drive motor per module.